One of the concerns of circuit designers is the control of circuit or component heat generated during operation of an electronic circuit. Such control is necessary in order to prevent component or circuit failure caused by a heat build up. The generally preferred method to control circuit and component heat is to dissipate it into the atmosphere before it can build up to damaging levels. In order to do this, designers will usually associate the components or circuit with a heat sink to absorb heat from the component or circuit and radiate it into the atmosphere.
Heat sinks are generally made of a material with favorable heat transfer, or thermal conductive, characteristics; that is, the material must be able to absorb heat and radiate it into the surrounding atmosphere in an efficient manner. Several metals have favorable thermal conductive characteristics, including copper, aluminum, steel, and their alloys. Any one of these materials can be used as a heat sink, but aluminum is generally the preferred material because copper is expensive and steel is not very malleable.
Heat sinks are made in a variety of shapes and sizes and several methods exist for combining heat sinks with circuits or components. Sometimes the heat sink is mounted directly to the heat generating component while at other times the entire circuit will be associated with a single heat sink. In the case of circuits mounted on small printed circuit or wiring boards, the entire circuit or wiring board will frequently have a single heat sink mounted on it. In most cases printed wiring and circuit boards that are small in size will require a single heat sink consisting of a single sheet of metallic material, such as aluminum, shaped to conform to the circuit with which it will be associated. Using prior art, the heat sink will be fastened to the circuit by a method or mechanism that will leave an air space for insulation purposes between the circuit board and the heat sink in order to prevent the metallic heat sink from shorting the circuit on the printed circuit or wiring board.
In many conventional devices, if a small flat printed wiring or circuit board is required to be associated with a heat sink, then a flat piece of aluminum of approximately the same size as the circuit board is designated for use as a heat sink. The circuit or wiring board and heat sink are typically mounted so they directly oppose each other. When in this configuration, the heat sink is able to absorb heat emitted by the circuit and components mounted on the board. The heat sink is typically held in place by using any one of several well recognized fastening means, such as clips, screws, pins, or bolts. Additionally, in order to keep the heat sink from coming into direct contact with the circuit or wiring board, spacers are used to keep the circuit board and the heat sink separated.
These conventional assemblies require several small parts that must meticulously be assembled, which generally means the manufacturing process is slower and more costly. Additionally, a number of assemblies are typically rejected for quality control reasons when numerous small parts are used because of the ease with which a part may be inadvertently omitted or come apart due to vibration and handling that occurs during the remainder of the assembly process.
Accordingly, what is needed in the art is a heat sink that can be associated with a circuit requiring heat control that has a simple attachment method and uses substantially fewer parts than prior art methods.